Vehicle navigation systems typically use position data from a global positioning system (GPS) system to determine a vehicle's location. Such systems also may include additional sensors such as an odometer or gyroscope to provide dead-reckoning navigation when GPS signals are lacking. In operation, the driver inputs a destination address into the vehicle's navigation system. The navigation system will then calculate the position of the vehicle and the route to be traveled, and guide the driver to that destination, using audible and visual instructions. The directions are derived from map data accessible to the system (e.g., stored on hard drive or CD ROM). Some systems integrate traffic information into the directions provided, thereby allowing the user to select less congested routes.
Such navigation systems, while helpful, are associated with a number of problems. One such problem is that many conventional navigation systems are not adaptive, and continue to make the same mistakes or otherwise provide undesirable directions repeatedly. For example, assume that a road called El Camino Real is slow (e.g., many traffic lights). A conventional navigation system, however, understands this road to be fast because it is also a numbered state route (CA Route 82), and therefore includes it in driving directions whenever possible, despite the driver's continued frustration with use of that route.
Some more advanced navigation systems can determine a driver's average road speed for roads frequently traversed, so that estimated travel times can be calculated. Other navigation systems can learn frequently driven routes, so that minimal instruction can be given for those routes (thereby distracting the driver less). Although such navigation systems provide additional driver support, they are still not sufficiently adaptive.
For instance, such systems fail to consider changes over time (e.g., rush-hour vs. weekend) and under different conditions (e.g., when road is under construction, different weather conditions, driver is in a hurry, local stadium event just ended, etc). In addition, conventional systems fail to consider multiple route attributes simultaneously; nor do they consider multiple conditions. Moreover, some such systems aggregate information from all users (as opposed to an individual user). These aggregate-based systems typically require a common infrastructure to be built (a centralized traffic database or server), and depend on getting a “critical mass” of early adopters for successful deployment. In addition, while such aggregated systems provide representative coverage, they fail to consider the relevance of personal driving history (e.g., the extent to which the individual driver departs from the mean in terms of driving style, preferences, and road knowledge).
What is needed, therefore, are adaptive navigation techniques.